Stock-Based Compensation Stock Option Summary (Details) (Employee Stock Option [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010
Employee Stock Option [Member]
[Line Items]
Outstanding, beginning balance, Number	1,102		1,179
Outstanding, beginning balance, Weighted Average Exercise Price Per Share	$ 55.21		$ 52.93
Outstanding, beginning balance, Weighted Average Remaining Contractual Term	5.58		5.90
Outstanding, beginning balance, Aggregate Intrinsic Value	$ 10,883	[1]	$ 22,863	[1]
Granted, Number	103		71
Granted, Weighted Average Exercise Price Per Share	$ 52.13		$ 61.97
Granted, Weighted Average Grant Date Fair Value	$ 21.81		$ 27.18
Exercised, Number	(29)		(144)
Exercised, Weighted Average Exercise Price Per Share	$ 19.53		$ 40.82
Exercised, Aggregate Intrinsic Value	1,050	[1]	4,413	[1]
Forfeited, Number	(63)
Forfeited, Weighted Average Exercise Price Per Share	$ 58.50
Expired, Number	(1)
Expired, Weighted Average Exercise Price Per Share	$ 7.00
Outstanding, ending balance, Number	1,112		1,106
Outstanding, ending balance, Weighted Average Exercise Price Per Share	$ 55.72		$ 55.11
Outstanding, ending balance, Weighted Average Remaining Contractual Term	4.68		5.83
Outstanding, ending balance, Aggregate Intrinsic Value	1,518	[1]	14,660	[1]
Vested and Expected to Vest, Number	1,106		1,096
Vested and Expected to Vest, Weighted Average Exercise Price Per Share	$ 55.74		$ 54.99
Vested and Expected to Vest, Weighted Average Remaining Contractual Term	4.65		5.80
Vested and Expected to Vest, Aggregate Intrinsic Value	1,518	[1]	14,449	[1]
Exercisable, Number	1,027		952
Exercisable, Weighted Average Exercise Price Per Share	$ 55.94		$ 52.25
Exercisable, Weighted Average Remaining Contractual Term	4.3		5.4
Exercisable, Aggregate Intrinsic Value	$ 1,518	[1]	$ 14,551	[1]

[1] The aggregate intrinsic value of outstanding stock options represents amounts that would have been received by the optionees had all in- the-money options been exercised on that date. Specifically, it is the amount by which the market value of Itron’s stock exceeded the exercise price of the outstanding in-the-money options before applicable income taxes, based on our closing stock price on the last business day of the period. The aggregate intrinsic value of stock options exercised during the period is calculated based on our stock price at the date of exercise.